Update badges

Ref stylelint/stylelint#29

Author: MoOx

README.md

@@ -1,4 +1,4 @@
-# cssnext [![NPM version](http://img.shields.io/npm/v/cssnext.svg?style=flat)](https://www.npmjs.org/package/cssnext) [![Travis Build Status](https://travis-ci.org/cssnext/cssnext.svg)](https://travis-ci.org/cssnext/cssnext) [![AppVeyor Build status](https://ci.appveyor.com/api/projects/status/q12sb37x4fpa7sht?svg=true)](https://ci.appveyor.com/project/MoOx/cssnext) [![Code Climate](http://img.shields.io/codeclimate/github/cssnext/cssnext.svg?style=flat)](https://codeclimate.com/github/cssnext/cssnext) [![Join the chat at https://gitter.im/cssnext/cssnext](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/cssnext/cssnext?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+# cssnext [![NPM version](http://img.shields.io/npm/v/cssnext.svg?style=flat)](https://www.npmjs.org/package/cssnext)  [![Travis Build Status](https://img.shields.io/travis/cssnext/cssnext.svg?label=unix build)](https://travis-ci.org/cssnext/cssnext) [![AppVeyor Build Status](https://img.shields.io/appveyor/ci/MoOx/cssnext.svg?label=windows build)](https://ci.appveyor.com/project/MoOx/cssnext) [![Join the chat at https://gitter.im/cssnext/cssnext](https://img.shields.io/badge/gitter%20-join%20chat%20%E2%9E%9E-1dce73.svg)](https://gitter.im/cssnext/cssnext)
 
 
 > Use tomorrow's CSS syntax, today.